1. Field of the Invention
The present invention relates to apatite having glucanase immobilized therein, and to a method of immobilizing glucanase in apatite. "Glucanase" which is a general term for glucan-decomposing enzymes includes various enzymes. It is understood, however, that the term "gulcanase" used herein refers to levanase which decomposes levan, dextranase which decomposes dextran, and mutanase which decomposes mutan. Further, the term "apatite" refers to both hydroxyapatite and fluoro-apatite.
It is well-known that the occurrence of dental caries is due to dental plaque formed by way of polysaccharides such as, levan, dextran and mutan which are produced by a variety of oral bacteria. Consequently, it is believed that the polysaccharides produced by such bacteria should be removed to suppress the occurrence of dental plaque for the purpose of preventing dental caries. The present invention relates to apatite having immobilized enzymes for the decomposition of polysaccharides associated with dental caries, and to a method of preparing such apatite.
2. Description of the Prior Art
In the prior art, various methods have been developed for removing dental plaque in order to prevent dental caries. Such methods include scraping-off of dental plaque with the use of polishing agent such as zeolite, calcium carbonate, alumina and silica, using dextranase together with a stabilizer, etc. Until now, however, there has been no method of immobilizing enzyme, which are capable of decomposing polysaccharide responsible for the occurrence of dental caries such as levanase, mutanase and dextranase, with apatite, and there has been no apatite in which such enzymes are immobilized, as contemplated in the present invention.
Glucanase is an enzyme and relatively unstable. Accordingly, when glucanase is mixed with a dentifrice without being modified, its activity decreases with time and eventually vanishes. Dextranase is now used with dentifrice, and various stabilizers are produced to prevent the deactivation thereof. For instance, combinations of dextranase with aluminium oxide, carvone or l-mentol, and gelatin or peptone are proposed in the specifications of Japanese patent application Laid-Open Nos. 56-63915 and 56-110609 and Japanese patent publication No. 52-49005. Because dentifrice is designed to be used in the mouth, various restrictions are imposed including considerations concerning the influence upon the human body and the demand for a refreshing feeling after use. Because it is a matter of course that such restrictions are placed upon the stabilizers used, the selection of the stabilizers involves difficult problems. Use of other enzymes besides dextranase possess the same problems as the use of dextranase.